1. Field of the Invention
The present invention relates to a method of processing and a processing system of a gaseous volatile organic compound. The present application is based on Japanese Patent Application No. 2006-045074, filed Feb. 22, 2006, the content of which is incorporated herein by reference.
2. Description of the Related Art
In factories which use various types of volatile organic compounds such as toluene, xylene, or the like, there are serious concerns regarding disposal of the volatile organic compounds after use. If the amount of discharge or disposal is small, discharge gas containing the used volatile organic compounds may be discharged into the atmosphere within a range that falls below an environmentally acceptable value. However, if the discharge amount is large (which it is in the majority of cases), this is dealt with by providing separate type of equipment for treatment.
As a conventionally used method of processing, the discharge gas containing the volatile organic compound is firstly supplied to an adsorption apparatus where the volatile organic compound is adsorbed in an adsorbent. The adsorbent which has been adsorbed the volatile organic compound is then desorbed in steam so that the volatile organic compound is mixed with the steam. Next, steam which has adsorbed the volatile organic compound is condensed, and the condensed water is distilled so that the volatile organic compound and the water are separated. Finally, the volatile organic compound separated from the water is combusted and decomposed.
In the conventional treatment method, in addition to the cost necessary for constructing/installing a treatment facility, the running cost of the facility also increases. Accordingly, a technique has been proposed for processing and decomposing a volatile organic compound, without incurring extra costs, by using an existing gas turbine provided in a factory (see, for example, Japanese Unexamined Patent Applications, First Publications No. 2003-322324, No. 2004-036492, and No. 2004-184003).
In the invention disclosed in Japanese Unexamined Patent Application, First Publication No. 2003-322324, a hazardous substance generated from a volatile organic compound is scavenged therefrom, and supplied to an air intake port of a gas turbine, and then compressed along with air in a compressor. The compressed air containing the hazardous substance is supplied to a combustor and fuel gas is concurrently supplied thereto, and they are combusted to thereby drive a turbine. The hazardous substance is combusted in the combustor and thus rendered harmless, and then discharged into the atmosphere together with exhaust gas of the gas turbine.
In the inventions disclosed in Japanese Unexamined Patent Applications, First Publications No. 2004-036492 and No. 2004-184003, waste fluid containing a volatile organic compound is directly supplied to a combustor and fuel gas is concurrently supplied thereto, and they are combusted to thereby drive a turbine. The waste fluid containing a hazardous substance is combusted in the combustor and rendered harmless, and then discharged into the atmosphere together with the exhaust gas of the gas turbine.
However, in the above described treatment method, the following inconveniences are pointed out. In the invention disclosed in Japanese Unexamined Patent Application, First Publication No. 2003-322324, a structure thereof is such that the hazardous substance generated from the volatile organic compound is supplied to the air intake port of the gas turbine, however, a part of the intake air is not introduced to the combustor, but is used in the subsequent stage or in cooling the turbine. Therefore, some of the hazardous substance does not pass through the combustor. In other words, it is discharged from the gas turbine without being combusted, that is, it is not sufficiently treated. Further, in the inventions disclosed in Japanese Unexamined Patent Applications, First Publications No. 2004-036492 and No. 2004-184003, waste fluid with a high concentration of hazardous substance is directly supplied to the combustor, and therefore, there is concern that the flame temperature may become excessively high.